The invention relates to a crop lifter for harvesting machine reaping systems which include a bed plate with projecting reaping fingers to which the crop lifters are attached.
In known reaping systems, reaping fingers are distributed along the bed plate. The fingers guide a cutter bar and form the counter cutting edge for the cutting edges of the reaping blades attached to the reciprocating cutter bar. In order to reap bent or lying cereals, crop lifters may be used to lift the cereal. These crop lifters include a support bar with its first end retained on the bed plate. Also, the crop lifter is supported, via a holder and holding means attached thereto, at the tip of the reaping finger. The second end of the support bar is connected to a grain lifter. The grain lifter is arranged at an angle to the support bar. The holder holds the crop lifter parallel to the driving direction of the harvesting machine. The support bar is preferably a spring steel. Thus, the crop lifter with its tip, formed by the connection area of the grain lifter with the support bar, can be guided on the ground and follow the ground unevennesses. The holder moves relative to the tip of the reaping finger. The holder itself is riveted to the support bar. Such a crop lifter is described in DE 43 23 053 A1.
Modem reaping systems for harvesting machines, for example combine harvesters, include reaping fingers arranged, in most of the cases, inclined in their working position in a range of 12xc2x0 to 18xc2x0 downwards to the ground. The angle achieves a corresponding gap with respect to the ground for the cutting tools tray following in a direction opposite to the movement of the harvesting machine in the reaping operation. Also, the angle enables sufficiently low mowing. The crop lifter support bar in the mounted condition is also inclined to the ground for the same reason.
starting from the tip of the reaping finger. The inclination is changed to a direction of the The inclination towards the ground has to be changed at least support bar parallel to the ground. If the angle is not changed, the crop lifter would contact the ground too steeply and would be pushed into the ground. Thus, the support bar is bent upwards.
The support bars are often bent upwards in the area of or at the holder to achieve a gap between the holder and the gliding portion close to the grain lifter of the support bar. The support bars are then directed downwards up to the gliding portion and thus down to ground contact. Thus, the gliding portion rests on the ground. This gliding portion is formed crosshead shoe-like and the grain lifter is welded to its tip. The crosshead shoe-like portion of the support bar is arched downwards, when seen in cross-section, so that its side edges do not cut into the ground when the crop lifter is loaded sideways when driving around bends.
Such a crop lifter is described in GB-PS 1 396 078. Its support bar is archedly profiled downwards in the gliding portion and upwards in the following portion in the direction towards the holder. The transition from the downwards directed arching to the upwards directed arching is achieved between the portion used as a gliding portion of the support bar and its portion rising towards the holder. However, on the transition there is no reinforcement of the support bar by a profile. Here, the support bar buckles, when the grain lifter is heavily loaded
A crop lifter is described in DE-PS 1 188 853. Here the support bar is attached by a holder above a reaping finger. The support bar is not provided with a profile in its gliding portion. Only its portion steeply rising to the holder is provided with a profile. The support bar has, because of this, spring characteristics only in the gliding portion parallel to the ground.
A crop lifter is described in DE-OS 25 31 435. Here the support bar is provided with a profile archedly downwards or upwards in the area of the holder. The support bar is not provided with a profile from the grain lifter attachment area to the holder.
These known crop lifters have several disadvantages. For example, when the grain lifter is loaded by strong crops, the support bar is elastically deflected in a buckling way straight away behind the gliding portion. In the embodiment according to DE-PS 1 188 853 the support bar deflects generally in the middle of the gliding portion. This leads to the tip of the crop lifter bending upwards. Thus, grain lodged in the crop lifter exits from the crop to be harvested. Accordingly, when an individual crop lifter bends upwards, the neighboring crop lifter, however, does not bend. Thus, the straw of the one crop lifter is pressed downwards and the straw of the neighboring crop lifter is pressed upwards. This straw build-up cannot be transported anymore to the back of the harvester and leads to a blockage of the cutter bar. The driver must reverse the machine, to remove the straw build-up from the cutter bar.
The present invention provides a crop lifter with the end of the support bar, close to the attachment area of the grain lifter, even under stronger loading of the grain lifter, remains approximately constant in its orientation to the ground.
The harvesting machine reaping system has a bed plate with projectingly attached reaping fingers to which a crop lifter is attached. A support bar has a first end and a second end. The first end serves to retain the support bar on the bed plate. A grain lifter is connected to the second end of the support bar. A holder is attached on the support bar between the first end and the second end. Retaining means is attached to the holder. The retaining means is arranged at a distance to the support bar and is supportable on the reaping finger. The holder, together with the retaining means defines a free motion gap. The gap enables an approximation of the support bar to the reaping finger.
The support bar is formed with a rigid flexure in an area between the second end and the holder. Also, the support bar is formed with an elastic flexure in an area between the holder and the first end.
Springing of the support bar is extremely limitedly or completely eliminated in the area between the end of the support bar, attached to the grain lifter, and the holder. If the gliding portion of the support bar of the crop lifter is pushed upwards by a ground elevation, the support bar does not spring upwards directly behind the grain lifter. Also, there is very limited springing in the area between the gliding portion and the holder. However, the springing area is displaced behind the holder to the area between the holder and the first end of the support bar. Vertical movement is provided vertically in the holder relative to the tip of the reaping finger. This movement enables the tip of the crop lifter to be lifted upwards up to 10 cm relative to the tip of the reaping finger. Accordingly, the tip can avoid, due to the movement, ground elevations. The further the spring elastic bending is displaced backwards of the first end, the less the inclination angle of the tip of the crop lifter changes with reference to the reaping finger. The gliding portion of the support bar of the crop lifter remains in contact to the ground over a longer portion. Thus, wear is reduced. This portion when loaded is also not guided out off the crop to be harvested. The support bar is also more stable in this area due to a more or less strong contoured profile corresponding to the requirements for a rigid formation. Thus, a weaker raw material can be used which leads to a reduction of cost.
In an embodiment of the invention, the support bar is formed with a rigid flexure, by a contour in the area between the second end and the holder. This refers especially to the area which follows the area of the attachment of the grain lifter on the support bar starting from the second end of the support bar in the direction towards the holder. The immediate area at the second end is already sufficiently reinforced by the attachment of the grain lifter on the support bar. Thus, the provision of a profile or contour is applied in the crosshead shoe-like area. The support bar crosshead shoe-like area abuts the ground and extends to the holder.
The elastic flexure design for the portion between the holder and the first end means that a deflection of this portion takes place when the grain lifter is loaded in a way which exceeds the normal loading during the normal reaping on a level surface. In this case, the support bar should move closer to the reaping finger within the gap of free motion in the holder. Preferably, the support bar is arched in the portion from the second end or the attachment area of the grain lifter on the support bar up to the holder.